Device for applying abrasive tool covers



y 1933. F. RICKS ET AL 1,917,329

DEVICE FOR APPLYING ABRASIVE TOOL COVERS Origirial Filed April 17, 1926 Patented July 11, 1933 UNITED STATES PATENT OFFICE EEED :aIcKs AND ED-VIARD E EnEErcK TQWNDROW, or LEICESTER, ENeLANnnssIe-N- one To UNITED SHOE MACHINERY CORPORATION, OF PATERSON, NEW JERSEY,

v A CORPGR-ATIQN OF NEW JERSEY DEVICE FOR APPLYING ABRASIVE TOOIII. COVERS Original application filed April 17, 1926, Serial No. 102,688, and in Great Britain April 25, 1 925. Divided V and this application filed December 2, 1930, Serial 110.49%),528. Renewed June 30, 1932.

This invention relates to devices for applying abrasive covers to tools of the Naumkeag type and is" herein illustrated as embodied in a device suitable. for applying covers of the type illustrated in our copending application Serial No. 102,688, filed April 17 1926, of which this application is a division.

The abrasive'cover disclosed in our abovementioned copending application is therein described in relation to a Naumkeag tool of the type disclosed in United States Letters Patent: N 0. 1,227,622, granted May 29', 1917 upon the application of Ernest Hope. This tool comprises a rigid supporting member covered with a resilient non-inflated pad of cellular structure. For a purpose later to be explained, both the abrasive cover and the resilient pad may be provided with a central perforation; the abrasive cover being molded to give its active central surface a radius of curvature shorter than that of the corresponding surface of the resilient pad, with the result that when the pad cover is applied to the tool its central portion is spaced a substant-ial distance from the resilient supporting pad even though the marginal portions are drawn up tightly and clamped to the tool, thereby producing a relatively soft action. The marginal portion of the cover is slitted to form tabs which are clamped to the upper face of the tool.

In accordance with a feature of the present invention, the illustrated cover-applying device comprises a cup-shaped holder having a spacing member adapted to be brought into engagement with the rigid portion of the Naumkeag tool to allow contact of the pad cover with'the pad around its periphery but constructed and arranged to keep the holder at a predetermined distance from the pad thereby to prevent the holder from forcing the central portion of the cover against the pad while the tabs of the abrasive cover are bent inwardly to enable them to be clamped to the tool; The purpose of thus maintaining the central portion of the cover away from the surface of the pad is to insure a softer abrading action than would be possible if the central portion of the. cover were to be directlybacked up by the pad. In the through the perforations of the cover and of I the pad and is constructed and arranged to contact with a stop formed upon the rigid portion of the tool inorder to provide a space between the central portion of the pad cover and the pad. I r

In accordance with a further feature of the invention, the cover-applying device "comprises tab-bending mechanism which acts upon the outer surface of the tabswith a movement which is both inward and circumferential with respect to the axis of the abrasive cover. These combined movements result in a wiping action against the outer surfaces of the tabs which serves to deflect the tabs inwardly in overlapping relation. In the illustrated device this mechanism comprises a plurality of members having edges for engaging the outer surfaces of the tabs and means for inclining the members to bend their edges into non-tangential inclined relation to the circumference defined by the tabs. These members, as shown, consist of segmental plates supported forlimited circumferential and inward radial movement.

The invention further consists of various features of construction and combinations and arrangements of parts herein shown and claimed, the advantages of which will be apparent to those skilled in the art from the following description, reference'being had to the accompanying drawing, in which Fig. 1 is an elevational view, partly in section, showing an abrading tool with the abrasive cover attached thereto;

Fig. 2 is aplan view of a blank from which the abrasive cover is formed;

Fig. 3 is a plan view of the cover-applying tool; and

Fig. 4

in operation.

is an elevational view, partly in 1 section, illustrating the cover applying'toolkeag pad of the non-inflated type'shown ,in-

the above-mentioned Letters Patent No. 1,227,622. In this tool a rigid, circular, disk shaped head or support 10'is secured to or formed upon the lower end of a threaded stem 12 by means of which the tool may be rotatably mounted in a machine. Upon this head 10 is mounted a circular pad 14 of rubber or the like provided with a convex working face 16. This face is supported by means of a plurality of intersecting ribs 18 formed upon the inner surface of the pad to provide a series of polygonal pockets or cells completed by the end surface of the disk 10 as the upper edges of the ribs 18 bear against said disk; A hole 20 is provided at the center of the pad for a purpose to be later explained and registering with this hole is a concentrically disposed recess 22 formed in the head 10 and of smaller diameter than the hole 20. It will be observed that an abrasive cover 24 has been applied to said pad, engaging it tightly around the periphery but spaced therefrom, as at 26, a substantial amount.

The marginal portion of the cover is folded over the upper surface of the pad with the tabs 28 of said cover in overlapping relation and gripped against the upper surface of the pad by means of a clamping coverplate 30.

A spring 32 is interposed between the disk 10 and the cover plate 30 for a purpose which will later appear, and a clamping nut 34 is provided upon the stem 12 by means of which the cover plate may be clamped firmly against the marginal tabs of the cover to grip them upon the pad 14. The abrasive cover is provided with a central opening 36 which registers with the hole 20. The tool is intended to rotate in a counterclockwise direction when viewed from above as indicated by the arrows in'vFigs. 1 and 2, and it-will be seen that the pad cover, when applied to the tool, has a minimum of such local protuberances of folded or bent-up material at the end of the slits as would promote undue wear of the cover. Furthermore, the overlapping relation of tabs 28 of the cover at or immediately adjacent to the edge of the tool is in such relation to the rotation of the tool that any contact of a piece of work with the tool at his portion tends to lay'the tabs down on each other rather than to tear them apart.

To promote this result'the cover is prefer-' ably formed from a disk 40 of abrasive material shaped as in Fig. 2. Such disks 40 are preferably'first cutfrom sheets of abrasive material, such as emery cloth, by properly shaped knife-edged dies in, apress in the usual manner. the dies employed having portions projecting inwardly at intervals to out slits in the margin of the disk which form the tabs to be folded over the pad. The centralperforation to be later produced is indicated at 36.

After'such disk-shaped pieces have been cut out, they are molded so that the central active portion or operative face of the cover has a curvaturethe radius of which'is less than the radius of the corresponding face 16 of the pad, and the marginal tabs ofthe disk are turned in upright position in proper overlapping relation, as shown in Fig. 4, ready for the application of the cover to the pad. An apparatusfor molding the abrasive covers is disclosed and claimed in our copending application Serial No. 592,351, filed February 11, 1932, which also is a division of our above-mentioned copending application Serial No. 102,688.

The cover'applying device which constia;

tutes thesubject-matter of the present application is illustrated in Figs. 3 and 4. It

comprises a cup-shaped member provided with an axial stem 112 serving as a handle.

The cup-shaped member 110 is recessed with an internal curvature which is complemental to the convex curvature of the pad cover 24, and said cover may be readily positioned within the cup of the applying device by means of acentrally located pin 114 arranged to engage the central perforation 36. of-the cover and adjustably mounted in the stem 1.12 by threads 115. This pin is provided with a pointed and reduced end 116 forming be tween the two portions of the pin a shoulder between the central part of the cover and the V N pad. The design of the recess in the applying J device 110 is such that when the shoulder 118 of the central pin 114 contacts with the rigid portion of the pad the edges of the recess in the cup will press the peripheral portion of the cover firmly against the corresponding portion of the pad with the marginal tabs in upstanding relation as indicated in Fig. 4. These tabs 28, as indicated in Figs. 1 and 4, overlap each other progressively in a direction opposite to the direction of rotation, and 3 the applying device, after it has positioned the cover 24 as above described, is constructed and arranged to fold these tabs 28 in over the upper face of the pad 14 in order that they may be engaged by the cover plate 30 which,.for the purpose of this operation, is held up by a spring 32.

' To this end, vertical superposed ringsv 120 and'1'22 are mounted upon the upper face of the applying device 110 and retained in position thereon by means of headed pins 124, four of which are provided about thedevice. The upper plate 120 is provided with circumferential slots 126 surrounding said pins 124 so that itmay be moved concentrically about i the axis of the applying device for a limited dlstance.

provided upon the upper ring 120. The

lower ring 122 is clamped upon the apply-' 111g device 110 by means of the bolts 124.

For this purpose a handle 128 is.

' 136, inclusive.

Between the ring-shapedplates 120 and122 inner peripheries, which portions, when the segments are 1n closed position as w1ll laterbe described, serve to make a more '1 1early contmuous r ng-like surface'contacting with the tabs 28 of the cover, Theflarrangement of the device is such thatrotative movement of the upper ring 120 under actuation of the produce a combined rotative and radialmovement of the various segmental plates 130 to To this end, each of said segmental plates is provided with a radial slot 144. Each slot is engaged by a depending pin 146 secured to the under side of the ring 120. One end of the segment 130 is providedwith a sharply inclined slot 148 while the other end of said segment is provided with a longer, less sharply inclined slot 150. Each of the other segmental plates is provided with corresponding slots at its respective ends. These slots surround the respective pins 124 and guide the ends of the segmental plates inwardly as they are rotated by movement of p the handle 128. During this movement the action of the respective slots 148 and 150 of the various segmental plates is such-that the trailing end of each of the segments moves inwardly faster than does the forward end,

thus producing an inward wiping action against the outer surface of the upstanding tabs 28 which, in combination with the wiping action of the plates due to their component of rotary movement, is calculated to deflect these A tabs inwardly in their preferred overlapping arrangement as initiated by the molding apparatus. After the handle 128 of the applying device has reached the limit of its movement it may be allowed to remain in this posi ton, holding the tabs down against the upper face of the pad 14 and supporting the weight of the applying device itself so that the operators hands are freed to depress the cover plate 30 and to bring down the clamping screw 34 to hold said plate against the various tabs. WVhen the cover has been clamped in position upon the pad, the applying device may be'removed by a reverse movement of the handle 128.

Having described our invention, what we claim as new .and desire to secure by Letters Patent of the United States is 1. A device for folding the peripheral tabs of an abrasive cover over the edge of the disk of a Naumkeag tool in which the radius of curvature of the face of the disk upon the tool is greater'than the radius of curvature of the corresponding face'of the pad, said device cbmprising a cup shaped holder having a spacingmem' or adapted to be brought into engagement with a rigid portion of the -Naumkeag pad to allow contact of the pad cover with the pad around its periphery and constructed and arranged to keep the holder at a predetermined distance from the pad thereby't'o prevent the holder from forcing the centralportion of the cover against the pad, and means. for folding in the peripheral tabs of the cover to allow the coverto be secured upon the pad.

' 2. A device for applying a cover to a Naumkeag pad having a resilient disk provided with a central opening to expose a rigid stop within the pad, said device comprising a cup-shaped support adapted to receive'a molded cover having a central perforation, and a pin at the bottom of said cup extending through the perforation of the cover constructed and arranged to contact with the rigid stop within the pad through the opening in the resilient member in order to provide a space between the central part of the pad cover and the pad.

3.- A levice for applying to a rotatable Naumkeag bufling tool a cover havinga plurality of peripheral tabs adapted to be bent intooverlapping relation around the edge of said tool comprising a support, and means for bending the tabs of the cover inwardly over the upper surface of the tool constructed and arranged to have an automatic component of rotary movement relatively to the cover about the axis of rotation of the tool in. a direction that is opposite to the direction arranged to co-operate with the pad cover to proach of the device to said pad.

In a device for applying a circular cover of abrasive material having upstanding peripheral tabs to a Naumkeagpad. means for engaging the outer surfaces of said tabs, and means for. moving said engaging means both inwardly and circumferentially of the axis of the cover to fold said tabs inwardly. a

6. A device for applying a cover of abrasive material to a Naumkeag pad, comprising a cover-supporting means, a rotatable member, and segmental plates actuated by movement of said member to produce a circumferential and inward radial movement of said plates for folding in the tabs of said cover, said device being constructed and ar ranged so that the ends of saidplates have a different speed of radial movement.

7. A device for applying a cover of abra-v 5) sive material to a Naumkeag pad, comprising a cover-supporting means, a rotatable ringshaped member, segmental plates supported for limited circumferential and inward radial movement under the actuation of said ring-shaped member for folding in the tabs of said cover, and means for guiding said plates constructed and arranged tocause the trailing ends thereof to move inwardly faster than do the advancing ends. 7 I

8. In a device for applying a circular cover of abrasive material having upstanding peripheral tabs to a Naumkeag pad, a plurality of members having edges forengaging the outer surfaces of said tabs, and means for inclining the respective members of said plurality tobring their edges into non-tangential 

